This invention relates to a technology with which information of an IT apparatus group that is a management subject is acquired in a concentrated manner in units in which an administrator of a datacenter or other infrastructures, or a host management product, uses information, to thereby reduce the gap between a time when a piece of management subject information is acquired and a time when another piece of management subject information is acquired within the unit.
Currently, there is such a trend in a market that resources of all IT apparatus in a datacenter are managed by using a product for managing the IT apparatus in a unified manner. Moreover, as a result of a prevailing server virtualization technology, the number of the IT apparatus and servers including virtual servers subject to the management tends to increase. In the related-art datacenter operation, a management server regularly acquires all pieces of information of IT apparatus that are management subjects in an order registered in advance (in the order of their IP addresses or the like). An administrator refers to information held in the management server as the need arises (for example, WO 2009/144969 A2).